Your item did not arrive.
You complained to the seller.
The seller ignored you.
You complained to eBay.
Did you file a formal Dispute? The dispute process starts in the Resolution Centre up at the right under Customer Support.
Without the formal dispute, eBay and Paypal will not act.
Was the Dispute opened within 45 days? There is a deadline.
Did you escalate the Dispute to a Claim? If not, eBay/PP assume the seller made things right and close the dispute.
Did the seller prove Delivery somewhere? If so, you would lose the Dispute.
You left feedback.
Was the FB removed? EBay will remove feedback that breaks their rules of decorum.
You can still get a refund.
Phone the 1800 number on the back of the credit card you really paid with. (PP is just the mediator). Ask for a chargeback. Have all your dates, transaction numbers and payment amounts ready to help the customer service agent.
But act promptly. Credit cards have deadlines too.